Ceramic housing for semiconductor components



June 11, 1968 J, 1, MCMANUS 3,388,302

CERAMIC HOUSING FOR SEMICONDUCTOR COMPONENTS original Filed oci. 22,1963 i s sheets-sheet i -ggg INVENTOR John J McManus AT T 'QRNE Y June1l, 1968 y J. J. MCMANUS i3,388,302v

CERAMIC HOUSING FOR SEMICONDUCTOR COMPONENTS original Filed oct. 22.1963 5 sheets-sheet y INVENTOR John J. McManus A TTORNEY June 11, 1963 JJ, MCMANUS 3,388,302

CERAMIC HOUSING FOR SEMICONDUCTOR COMPONENTS 1 145 10 INVENTOR John J.McManus ATTORNEY United States Patent O 3,383,302 CERAMC HUSlNG FRSElt'llCONDUSTOR CMPNLNTS lohn l". McManus, Manhasset, NX., assigner to@cors Porcelain 'lornpany, Golden, Colo., a corporation of ColoradoContinuation ot application Ser. No. 317,893, (Bet. 22, 1363.. Thisapplication Dec. 30, 1966, Ser. No. 699,266

i4 Claims. (Cl. SlT-2.34)

ABS'HRACT F THE DESCLSURE ln accordance with the invention there isprovided a `housing for semiconductor circuitry which comprises aceramic base and a ceramic top plate secured together to form thehousing, the ceramic base being provided with a series of accuratelyaligned cavities, each adapted to receive -a semiconductor and arrangedin a plurality of parallel spaced apart rows with `grooves connectingthe cavities in each row, each row of interconnected cavities andgrooves having on the floor thereof a thin conductive layer bonded tothe base for `making electrical connection with the semiconductors inthe cavities, each of these conductive layers extending over a surfaceof the cera-mic base which is on the exterior of the housing. The topplate is provided with a plurality of parallel spaced apart electricallyconductive coatings on the bottom surface thereof and extending acrosscavities of adjacent rows of cavities in the base for making electricalcontact with the semiconductors in the cavities, each of these parallelspaced apart electrically conductive coatings extending over a surfaceof the top plate on the exterior of the housing. ln the preferredembodiment each of the base and top plate is provided with a ledge whichextends Outwardly of the housing and over which the conductive coatingsof the base and top plate, respectively, extend.

This :application is a continuation of application, Ser. No. 317,893,tiled Gct. 22, 1963, now abandoned.

This invention relates to a microminiature ceramic matrix for high speedsemiconductor switching circuitry. The word microminiature is used.`herein to mean very small. A matrix constructed in accordance with myinvention, one embodiment of which is shown in the drawings, comprises abase member and a top plate, each of which may be only .SOO inch inwidth and .660 inch in length, but the invention is not limited to thesedimensions.

One of the objects of the invention is to provide a matrix thatfacilitates rapid assembly of multiple series of `diode silicon wafersinto a complex miniaturized electronic switching circuit which canreadily be incorporated as a single unit into an electronic system. Suchsystems are employed in computers for driving memory storage units. Useof the miniaturized electronic switching circuit of my invention permitsbuilding of much smaller computers than now are known. It can replacethe large printed circuit board Iwhich now is part of switchingcircuitry.

The construction of the matrix base shown and described herein providesa series of `accurately spaced and aligned square cavities orreceptacles for silicon wafer diodes. The cavities are machined to aprecise depth, and serve as means for positioning the diodes and assupport and protection for the diodes in the finished device.

Between the plurality of cavities l provide :a series of novel metallicconductors which are made part of the Imatrix and serve as diodeiunctions, electrical conductors and interconnectors with externallylocated devices. The metallic conductors are produced by interconnectingeach cavity by a groove to `an external termination recess, and.

by coating the floor of the cavity, groovev and termination d PatentedJune ll, 1968 lCC recess with an adherent metallic conductor, such asmolybdenum-manganese, lithium-molybdate or nickel carboxyl, andsubsequently plating the coated surfaces with a gold alloy, such as99.7% gold and .3% antimony.

Another object of the invention is to provide a plurality of `diodeseach in the form of a silicon wafer which can be evaluated prior tofinal assembly and be replaced if necessary without impairing theperformance of other silicon components or any section of the circuitryof the device.

Further, l provide in the matrix base accurately spaced slots whichserve to align the ceramic top plate electrical conductors with the topof the diodes in the base.

Means also are provided `for enclosing all the diodes in one hermeticpackage which, however, allows for the feeding through of metallicconductors. Thus I eliminate the necessity of providing for individualdiode packages and achieve greater packaging density.

Another Vobject of the invention is to produce a matrix for the purposesdescribed which embodies superior heat conducting materials. The baseand top plate ofthe matrix are made of high purity aluminum oxide ,and/or beryllium oxide. The etlicient removal of heat from the deviceresults in more stable performance, higher reliability and longer lifethan has heretofore been attained in switching systems.

Other objects and advantages will be apparent from the drawings andyfollowing specilication.

ln the drawings:

FiG. l is a top plan view of the base member of a matrix embodying myinvention.

FIG. 2 is a transverse vertical sectional view on an enlarged scale, inthe plane of the line 2-2 of FIG. 1.

FlG. 3 is a longitudinal vertical sectional vie-w on an enlarged scale,in the plane of the line 3 3 of FIG. l.

FIG. 4 is a bottom plan view of the top plate of the matrix embodying myinvention.

FlGr. 5 is a transverse vertical sectional view on an enlarged scale, inthe plane of the line 5 5 of FlG. 4.

FG. 6 is a top plan view of the assembled base and top plate of FGS. land 4 which `form the matrix, with diodes in the base cavities, showingin dotted lines the conductors of the top plate overlying the diodes andconductors in the base.

FiG. 7 is an elevational view showing the longitudinal side of the baseand end of the top plate thereon.

FlG. 8 is an elevational view showing the end of the base andlongitudinal side of the top plate thereon.

PEG. 9 is a longitudinal vertical sectional view, on an enlarged scale,in the plane of the line 9-9 of FIG. 6.

FIG. l0 is a transverse vertical sectional view, on an enlarged scale,in the plane of the line litilil of FIG. 6.

Referring first to FiGS. 1 3, in that embodiment of the invention shownin the drawings, the ceramic base 2o is rectangular and has a flatbottom 21 and hat top surface 22. T he ceramic material preferably ishigh purity aluminum oxide and/or beryllium oxide which has superiorheat conduction properties. The flat top is provided with a plurality ofseries of square cavities 23 of uniform depth, arranged in parallel rowsextending longitudinally of the base 2o. The cavities 23 of each row areconnected by grooves 24 of the same depth as the cavities, said groovesbeing located midway between the sides of the cavities and alignedlongitudinally of the base. The end groove 24 of each row communicateswith an elongated termination recess 25 of the same depth as thecavities 23 and grooves 24. The termination recesses 25 extend fromalternate rows of cavities toward one end of the base and from the otherrows of cavities toward the opposite end of the base.

The cavities 23 are square, flat bottomed, machined to a precise depth,and accurately spaced and aligned. The

cavities 23, grooves 24 and termination recesses 25 have iloor surfacesin one horizontal plane. The door surfaces are coated with an adherentmetallic conductor which may be molybdenum-manganese, lithium-molybdateor nickel carboxyl. The metallic conductor coating need be only.OOM-.0002" thick, and is subsequently plated with a gold alloy such as99.7% gold and .3% antimony, making the conductors .002 thick. Theplated metallic conductors on the oors of the cavities 23, grooves 24and termination recesses 25 are indicated at 26.

The cavities 23 of each longitudinally extending row of cavities areprecisely opposite the adjacent cavity of an adjacent row, the adjacentcavities being separated by a narrow partition 27 slotted as indicatedat .8, to form an open top clearance groove which extends transverselyof the base across the center of transversely aligned cavities Z3 forreceiving and positioning top plate electrical conductors to bedescribed hereinafter. The slots 2S are not metallized.

A glass frame 29, thin, tiat and rectangular in shape, rests on the baseto surround the cavities 23 and grooves 24, and crosses the terminationrecesses as shown in FIG. l.

After the application of the metallic conductor coating and plating 26to the iioor of the cavities 23, grooves 24 and termination recesses 25,the base cavities receive and support silicon wafer diodes 30, not shownin FIGS. 1-3, but shown in the assembled matrix (FIGS. 6-10).

A top plate 3i is shown in FIGS. 4 and 5. It is made of the same ceramicmaterial as the base 20, and preferably is rectangularin shape and hasthe same top and bottom surface dimensions as the base. The top surface32 is at. The bottom surface 33 also is flat but recessed to providetermination recesses 34. inclined surfaces 35' join the bottom surface33 to the recesses 34. A series of narrow, elongated, parallel surfacesof the bottom 33 are metallized and gold plated to form electricalconductors 36 as shown in FIG. 4. The conductors 36 extendlongitudinally of the top plate 3l but transversely of the base 20, inthe clearance grooves formed by the slots 28, in the assembled matrix asshown in FIGS. 6-10. The conductors 36 are connected to terminationconductors 37 produced by metallizing and plating the terminationrecesses 34. The conductors 37 extend from alternate conductors 36 toone side edge of the top plate and from the other conductors 36 to theopposite side of the top plate, as shown in FIG. 4. The metallizing andplating is the same as described in connection with the coating 26.

Referring to FIGS. 6-10, the assembled matrix comprises the base member20 and top plate 3i, silicon wafer diodes 30 and glass frame 29. The topplate 31 has its surface 32 on top and the surface 33 with electricalconductors 36, 37, thereon, facing downwardly. In the assembledpositions of the two major parts, the longitudinal dimension of the topplate extends transversely of the base, so that electrical conductors 36on the bottom of the top plate extend at right angles across theelectrical conductors 26 in the rows of cavities 23 and grooves 24 ofthe base 20, and across the silicon wafer diodes 39 in the cavities 23.Thus the termination conductors 37 are accessible at opposite sides ofthe assembly and the conductors 25 are accessible at opposite ends ofthe assembly as shown in FIGS. 6, 7 and 8.

Registering holes 38 and 39 in the base 20 and top plate 3l,respectively, receive countersunk screws 40, for final assembly of theparts in accurately aligned relationship.

Changes may be made in the dimensions and details of construction andform of some of the parts without departing from the scope of theinvention. For example, the position of the termination conductors 26and 37 on all four sides of the assembly is desirable for certainswitching applications, but where all terminations are desired on oneside only, minor modification ofthe conductor configuration can be madewithin the scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are deined as fOllows:

1. A ceramic matrix `for high speed semiconductor switching circuitrywhich comprises (a) a ceramic base provided with (a-l) a series ofaccurately aligned cavities arranged in a plurality of parallel spacedapart rows, (a-Z) grooves connecting the cavities in each row, (a-3) atermination recess in the base located at an end 0f each row of cavitiesin communication with the cavities and grooves of the row, (a--4) anelectrically conductive coating on the floor of the cavities, groovesand termination recess of each row, (b) a diode in each cavity incontact with the conductive coating, (c) a ceramic top plate providedwith (c-l) a plurality of parallel spaced apart electrically conductivecoatings on the bottom surface of the top plate each extending acrosscavities of adjacent rows of cavities in the base and in contact withthe diodes in said cavities, (c-2) a termination electrically conductivecoating connected to an end of each of said parallel spaced apartelectrically conductive coatings on said top plate, (d) means connectingthe base and top plate together in superposcd relationship, and meansbetween said base and top plate surrounding the recesses in the base andproviding an hermetic seal for all the diodes in one package.

2. The ceramic matrix defined by claim 1 in which the ends of the baseextend beyond the side edges of the top plate, and the ends of the topplate extend beyond the side edges of the base, whereby the conductivematerial in the base termination recesses and the terminationelectrically conductive coatings of the top plate are exposed andaccessible externally of the matrix.

3. A microminiature ceramic matrix for high speed cmiconductor switchingcircuitry, which comprises (a) a ceramic base provided in its top with(a-l) a series 0f accurately aligned cavities arranged in a plurality ofparallel spaced apart rows extending longitudinally of the base, (at-2)grooves connecting the cavities in each row, (a-3) a termination recessin the `base located at an end of each row of cavities in communicationwith the cavities and grooves of the row, (a-4) the cavities, groovesand termination recess being of equal depth, (a-S) an electricallyconductive coating on the floor of the cavities, grooves and terminationrecess of each row, (b) a diode in each cavity in contact with theconductive coating, (c) a ceramic top plate provided with (c-l) aplurality of parallel spaced apart electrically conductive coatings onthe bottom surface of the top plate each extending across cavities ofadjacent rows of cavities in the base and in contact with the diodes insaid cavities, (c-Z) a termination electrically conductive coatingconnected to an end of each of said parallel spaced apart electricallyconductive coatings on said top plate, (d) means connecting the base andtop plate together in superposed relationship, and means between saidbase and top plate surrounding the recesses in the base and providing anhermetic seal for all the diodes in one package.

4. The microminiature ceramic matrix defined by claim 3 in which thecavities of adjacent rows are separated by a narrow partition which isslotted transversely between adjacent cavities, and the electricallyconductive coatings of the top plate extend transversely of the base insaid slots and are thereby aligned with the diodes in the base.

5. rI`he microminiature ceramic matrix defined by claim 3 in which theends of the base extend beyond the side edges of the top plate, and theends of the top plate extend beyond the side edges of the base, wherebythe conductive material in the base termination recesses and thetermination electrically conductive coatings of the top plate areexposed atnd accessible externally of the matrix.

6. The microrniniature ceramic matrix dened by claim 3 in which the baseand top plate are made of high purity aluminum oxide.

7. The microminiature ceramic matrix defined by claim 3, in which thebase and top plate are made of high purity beryllium oxide.

A microrniniature ceramic matrix for high speed semiconductor circuitrywhich comprises (a) a ceramic base provided with (a-l) a series ofaccurately aligned cavities arranged in a plurality of parallel spacedapart rows, the cavities of cach row being interconnected by grooves,(a-2) a termination recess in the vbase located at an end of each row ofcavities in communication therewith, (a1-3) an electrically conductivecoating on the tloor of the cavities, interconnecting means andtermination recess of each row, (b) a diode in each cavity in contactwith the conductive coating, (c) a glass frame on the base surroundingthe rows of cavities and extending across the termination recesses, (d)a ceramic top plate provided with (d-l) a plurality of parallel spacedapart electrical conductors on the bottom surface of the plate eachextending across cavities of adjacent rows of cavities in the base andin contact with the diodes in said cavities, (d-Z) a terminationelectrical conductor connected to an end of each of said conductors onsaid top plate, and (e) means connecting the base and top plate togetherin superposed relationship with the glass frame between them.

9. The microminiature ceramic matrix deiined by claim 8 in which theelectrical conductors in the base and top plate are accessibleexternally ofthe matrix.

10. The microminiature ceramic matrix defined by claim 8 in which thediodes are silicon wafers.

11. The microminiature ceramic matrix defined by claim 8, in which thetermination recesses extend from alternate rows of cavities in the baseto one end of the base and from the other recesses to the opposite endof the base.

12. The microminiature ceramic matrix defined by claim S in which thetermination electrical conductors extend from alternate electricalconductors on the bottom surface of the top plate to one end of the topplate and from the other electrical conductors to the opposite end ofthe top plate.

13. A ceramic package for semiconductor circuitry comprising a ceramicbase provided with a Series of aligned cavities each adapted to receivea semiconductor and arranged in a plurality of parallel spaced apartrows with grooves connecting the cavities in each row, an electricallyconductive coating on the floor of the cavities and the grooves of eachrow for making electrical contact with the semiconductors in thecavities of the row, a ceramic top plate provided with a plurality ofparallel spaced apart electrically conductive coatings on the bottomsurface of said top plate, each of said plurality of conductive coatingsextending across cavities of adjacent rows of cavities in the base formaking electrical contact with the semiconductors in the cavities, andmeans connecting the base and top plate together in super-imposedrelationship to form the package, each of said electrically conductivecoatings of said base member having a termination portion which extendsover a surface of said base member on the exterior of said package andeach of the electrically conductive coatings on said top plate having atermination portion extending over a surface of said top plate on theexterior of said package.

14. A ceramic package as set forth in claim 13 wherein the ceramic basehas an edge portion which extends beyond an edge of said top platethereby providing an exterior ledge on said package, said ledge 'beingthe exterior surface of said base over which the termination portion ofeach of said electrically conductive coatings of said base extends, andsaid top plate having an edge portion which extends beyond an edge ofsaid base thereby providing a second ledge on the exterior of saidpackage, said second ledge being the exterior surface of Said top plateover which the termination portion of each of the electricallyconductive coatings of said top plate extends.

References Cited UNITED STATES PATENTS 3,072,832 1/1963 Kilby 317-2353,195,026 7/1965 Wegner et al. 317-234 3,271,625 9/1966 Caracciolo317-101 3,271,634 9/1966 Heaton 317-234 3,292,241 12/1966 Carroll29-155.5

JOHN W. HUCKERT, Primary Examiner.

R. E. SANDLER, Assistant Examiner.

